"Our philosophy is simple -- when Apple brings a new subscriber to the app, Apple earns a 30% share," said Jobs in a statement released Feb. 15. "When the publisher brings an existing or new subscriber to the app, the publisher keeps 100% and Apple earns nothing."

At the time, Apple said publishers and content sellers would have to remove any links within their apps to outside-the-App Store purchasing options.

Last month, Apple relaxed part of the new rules, allowing developers to price their wares differently on the App Store and their own Web sites. However, the ban on all in-app links to external sales sites still held.

Some content sellers, including Rhapsody, had called Apple's demand for a 30% piece of the revenue pie "economically untenable" and said it would break their business models.

"[Adding] Apple's 30% will exceed the revenue on our product," said Jon Irwin, Rhapsody's president, in an interview shortly after Apple unveiled the new App Store rules last February. "It's not a matter of making less money, it would be zero profit."

Rhapsody updated its iPhone app last week to, among other things, remove the in-app subscribing link.

iPhone and iPad users who update their Amazon Kindle apps to today's version 2.8 can still purchase books from their devices, but must open Safari and manually steer to Amazon.com to do so.

To retain the Kindle Store button in the Kindle apps, users will have to decline today's update, as well as all future updates.

On Monday, Google also complied with Apple's new rules when it re-released Google Books -- which had been yanked from the App Store -- minus an in-app purchasing button.